Mods ... umm... everything except the body ... and even THAT was rebuilt... and modified.
5.3l all aluminum LS4 from a 2006 Pontiac Grand-Prix GXP: Tremec T5 from 2004 Mustang V6: Bellhousing from 1980s Jeep with 2.5l to adapt Ford T5 to GM 60* engine pattern: 1985 Corvette Dana 36 limited slip differential and entire rear end (narrowed): 2003 Crown Victoria front suspension and 12inch brakes: Rota Grid concave wheels 15x7 with 205/50/15 Falkens: Custom (hand built) chassis and subframes: Narrowed original GT6 steering rack: Custom sway bar: Custom exhaust (in progress!): ... yeah ... it's not done!
So back in the 70's dad test drove a GT6... he didn't buy it, but he's wanted one ever since.
I'm the youngest of four sons, am a trained Industrial Millwright, and have been into cars since I was a kid. (Maybe you can see where this is going)
We set a modest budget, and in June of 2014 we drove 1200kms round trip to bring this GT6 home from Sudbury, Ontario Canada.
The next four years involved learning how to do bodywork, and fortunately for me, there was no shortage of practice with the condition our car was in!
After finally hitting a wall with the project, we decided to change course and re-imagine the car with a completely new drivetrain. The old parts were sold to get another GT6 back on the roads, and we got to work.
A new frame was constructed from some fresh box tubing, and the C4 Vette rear end was narrowed and mounted. After messing around with anti-squat, bump-steer and camber, we could push up front.
All new geometry was required up here too, but of course this was a "bit" harder (ok a lot). More than a foot (30.48cm for our friends across the seas) was removed from the track width of the Crown Vic suspension, and the brake calipers were "strategically shaved" to fit in our new 15" wheels.
The original steering rack was repurposed, but due to the new geometry, was now too large. So ~5" was removed to correct bump-steer and a solid mount fabbed up. A custom sway bar followed suit and we could press on with the engine.
The LS4 is not commonly used, as it shares neither the bellhousing bolt pattern, nor starter mount of its siblings... this makes it cheap-ish! The bellhousing issue was solved earlier with the purchase of an old Jeep unit, but the starter motor required a different tactic... heavily based off a design from a gentleman on the BritishV8 forums. A gear-reduction starter and accompanying custom bracket, now meshes nicely with our custom flywheel, which adapts the LS crank pattern, to a 9" Centerforce clutch, which splines perfectly onto our stock late-model T5. Yay!
~300-350hp in a ~2200lb car should be fun… and with air conditioning someday, it should be enjoyable too!
With it rolled out into the sunshine for the first time in years, we could take-in our creation, and get fired up again to finish the rest of the work...
...Who knows how much longer THAT will take! The whole build is on YouTube to follow along :) youtube.com/fanatikbuilds
(P.S. I've ticked "Can we drive it?" ... but you may want to wait a bit longer!)